1. Field of the Invention
The present invention relates in general to guide rail assemblies used in assembly line and conveyor belt systems and, in particular, to an improved means for supporting and adjusting the position of a guide rail.
2. Description of the Related Art
Guide rails are used to direct the travel of articles along a predetermined path of an assembly line or conveyor system. The articles are conveyed on a belt or track during the processing and packaging procedures of a typical manufacturer. Dependable support and adjustment of the guide rails is important to ensure manufacturing efficiency and to prevent the articles from tipping over or falling off the conveyor system.
Typically, whenever a different article travels through the conveyor system, the guide rails must be adjusted to accommodate the specifications of that article. This entails adjusting the guide rails to certain horizontal distances from the conveyor system. Guide rail support posts have been developed which partially permit this adjustment procedure, but do not allow this procedure to be readily repeatable. That is, each time a different article was conveyed, the horizontal distance calibrations had to be performed anew. Depending on the complexity of the adjustments, this procedure could require a significant amount of time and cause unnecessary manufacturing downtime.
This nonrepeatability problem has been partially addressed by U.S. Pat. No. 5,492,218 issued to Falkowski, which teaches a railing support post that can be adjusted among predetermined fixed positions along a single axis perpendicular to the guide rail which it supports. Falkowski comprises a bracket that retains a support post, an elongated central member that is supported by the support post and has a handle and clamp which are affixed on opposite ends thereof, and a spring loaded sleeve that transfers an applied force on the handle to a spring force on the clamp.
Linear adjustment of the central member, and thus the clamp, is accomplished by mounting individual spacers of varied length along the central member between the sleeve and the clamp. In particular, to move a guide rail inwardly with respect to a conveyor belt, a large spacer is positioned in the mounting area located between the clamp on the central member and the sleeve.
Although Falkowski partially solves the nonrepeatability problem through use of a guide rail support post which permits adjustment, it has significant shortcomings. Most notably, due to tight tolerances, the device permits adjustment of the guide rail position only in the single direction along the centerline of the sleeve and perpendicular to the length of the guide rail. In particular, the central member of the Falkowski device is permanently affixed inside the sleeve by a base and ring device, and the spring mechanism is located inside the sleeve but outside the central member. This design results in successive circumferential layering where the central member is surrounded by the spring, which is then surrounded by the sleeve. This layering enables the support post to be adjusted along the centerline or axis extending through the sleeve, but prevents movement of the support post along all other axes.
This limitation on the range of adjustment of the device is a significant problem. When a force is applied to the handle to move the central member of the Falkowski device, that same force acts on the guide rails. This force is perpendicular to the attached guide rails, contorting them perpendicularly to their secured positions. Because the guide rails are fixed at other points along their length, the attempt to move a single portion of the guide rail inwardly or outwardly perpendicular to its length is resisted, with the guide rail bending or bowing instead of moving linearly which is desired. This may cause permanent bending and even breaking of the tightly affixed guide rails. Alternatively, it prevents the user from moving the guide rail to its intended position.
A second shortcoming of Falkowski relates to its spacer design. Because each individual spacer has a predetermined length, a user is required to have on hand many spacers of different lengths whenever the guide rail support post is adjusted. The unavailability of just one requisite length spacer causes unnecessary manufacturing downtime. Moreover, the Falkowski device incorporates a detent along its surface to secure the spacer to the central member. Because of this detent, however, the spacer cannot be easily cut to specification. That is, once the manufactured spacer is extruded and bored, an additional step is required to create the detent along the surface. Since this additional step is impractical to perform at the conveyor site, the spacers must be delivered to the conveyor site in a final configuration, rather than as a long member which can be cut and customized at the conveyor site.
A need therefore exists for a guide rail support post that permits a user to quickly, easily, and adjustably locate the guide rail in more than one position.